With forecasters predicting high temperatures hotter than a firecracker as the 4th of July approaches, a Heat Advisory has been posted for northeast Missouri and western Illinois.

The National Weather Service has posted the advisory for Audrain, Knox, Lewis, Marion, Monroe, Pike, Ralls and Shelby counties in Missouri, and Adams, Brown and Pike counties in Illinois.

The Heat Advisory runs from 11 a.m. Thursday until 10 p.m. Saturday.

Predictions call for high temperatures in the upper 90s and dewpoints in the low 70s, resulting in heat index values up to 107.

The weather services says that the combination of hot temperatures and high humidity will likely lead to an increased risk of heat-related stress and illness. The very young, the elderly, those without air conditioning and those participating in strenuous outdoor activities will be the most susceptible.

Also, car interiors can reach lethal temperatures in a matter of minutes.